WO2018040858A1 - Method and device for beam selection - Google Patents

Abstract

The present application provides a method for beam selection. The method comprises: a. preconfiguring beams of stages 1 to K as well as correspondences between beams of different stages; b. sending beams of stage 1 to a user terminal UE; c. receiving a beam index fed back by the UE; and d. determining a beam corresponding to the received beam index, if the determined beam is not a beam of stage K, sending to the UE beams of the next stage corresponding to the determined beam and then returning to c, and if the determined beam is a beam of stage K, serving the determined beams as a candidate beam selected by the UE. The present application can reduce overhead and improve accuracy in beam selection.

Description

Beam selection method and device Technical field

The present application relates to mobile communication technologies, and in particular, to a beam selection method and apparatus.

Background of the invention

At present, the fourth generation of mobile communication technology (4G) has begun to be widely deployed around the world, and the fifth generation of mobile communication technology (5G) has become an emerging research field. Large-scale multi-input multiple-output (MIMO) applications have become a hot area of 5G technology. Compared to traditional MIMO technology, massive MIMO can use more antennas at the base station (eNB) in order to provide greater throughput. At the same time, further application of beamforming technology under massive MIMO technology can achieve more precise directional services, so that more communication links can be provided in the same space, and the base station can be further improved by this spatial multiplexing. Service capacity.

Summary of the invention

An example of the present application provides a beam selection method. The method includes:

a, pre-configuring the correspondence between the first-level to the K-th beam and the beams at each level; wherein K is a natural number;

b. transmitting each beam of the first level to the user terminal UE;

c. receiving a beam index fed back by the UE;

d. determining a beam corresponding to the received beam index,

If the determined beam is not the K-th beam, transmitting each beam in the next-level beam corresponding to the determined beam to the UE, and then returning to c;

If the determined beam is a Kth order beam, the determined beam is used as a candidate beam selected by the UE.

An example of the present application also provides a basic battle for implementing the beam selection method described above, including:

processor;

a memory coupled to the processor; the memory having a machine readable instruction module executable by the processor; the machine readable instruction module comprising:

a configuration module, configured to perform beam selection configuration, and determine a correspondence between the first-level to the K-th order beams and the beams at each level; wherein K is a natural number;

a beam reference signal sending module, configured to send a beam reference signal to the user terminal UE;

a feedback receiving module, configured to receive a beam index fed back by the UE;

a control module, configured to: control a beam reference signal sending module to send a beam reference signal of the first-order beam configured by the configuration module to the UE; and after the feedback receiving module receives the beam index fed back by the UE, determine a beam corresponding to the feedback beam index of the UE And determining whether the beam is a K-th beam, if yes, the beam is a beam selected by the UE; if not, the control beam reference signal sending module sends a beam reference signal of the next-stage beam corresponding to the beam to the UE .

The embodiment of the present application further provides a non-transitory computer readable storage medium storing machine readable instructions, the machine readable instructions being executable by a processor to perform the following operations:

a, pre-configuring the correspondence between the first-level to the K-th beam and the beams at each level; wherein K is a natural number;

b. transmitting each beam of the first level to the user terminal UE;

c. receiving a beam index fed back by the UE;

d. determining a beam corresponding to the received beam index,

If the determined beam is not the K-th beam, transmitting each beam in the next-level beam corresponding to the determined beam to the UE, and then returning to c;

If the determined beam is the Kth beam, the determined beam is selected as the UE. Selected candidate beam.

The beam selection scheme described in this application does not need to send candidate beams to the UE for measurement one by one, so that the overhead of the beam selection process can be greatly reduced in the case where the number of candidate beams is large. In addition, in the beam selection scheme described in the present application, the width of the upper beam is required to be greater than the width of the lower beam. Therefore, the UE first selects from a wider beam and then selects from a narrower beam. Better against the influence of phase noise on beam selection accuracy, improve the accuracy of beam selection, and thus ensure communication quality.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the present application, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some examples of the present application. For the ordinary technicians, other drawings can be obtained from these drawings without any creative work. among them,

Figure 1 shows an example of beams of each stage as described in one example of the present application;

2 shows a flow chart of a beam selection method according to an example of the present application;

Figure 3 shows the process of beam selection by a base station and a single UE;

4 shows a process in which a base station performs beam selection with multiple UEs;

FIG. 5 is a flow chart showing a beam selection method according to another example of the present application; FIG.

6 shows an example of phase fine adjustment of a selected beam as described in one example of the present application;

7 is a flow chart showing a method for performing phase fine adjustment on a selected beam according to an example of the present application;

8a and 8b show an example of phase fine adjustment of a selected beam as described in another example of the present application;

FIG. 9 is a schematic diagram showing the internal structure of a base station according to an example of the present application.

FIG. 10 is a schematic diagram of another internal structure of a base station in an embodiment of the present application.

detailed description

The technical solutions in the present application will be clearly and completely described in the following with reference to the accompanying drawings. It is obvious that the described examples are a part of the examples of the present application, and not all examples. All other examples obtained by a person of ordinary skill in the art based on the examples in the present application without creative efforts are within the scope of the present application.

As mentioned earlier, more antennas and more beams can be obtained by combining massive MIMO technology with beamforming techniques. For example, the number of beams that can be used in a 5G system can reach 512 or even more. As the number of antennas and the number and accuracy of the beams increase, the capacity of the system can be greatly improved. Moreover, as the number of beams increases, the width of each beam becomes narrower and narrower, so that more precise directivity services can be realized. In this case, how the mobile terminal (UE) performs beam selection has become one of the problems to be solved in the 5G communication system.

As mentioned above, when large-scale MIMO technology is applied, the number and accuracy of the beams that can be generated will be greatly increased. If all the beams are sent to the UE one by one in an exhaustive manner, the UE will measure and select one by one. This will result in very large signaling overhead. To this end, an example of the present application provides a beam selection method for beam selection by hierarchically selecting beams, thereby avoiding excessive signaling overhead in the beam selection process.

In the example of the present invention, the basic configuration of beam selection is first required before beam selection. These configurations mainly include the following aspects:

First, the number N of candidate beams to be selected is determined. In an example of the present invention, a beam generated by a base station that can be selected by a UE is referred to as a candidate beam. The number of candidate beams described above may be related to the number of transmit antennas of the base station. After the configuration of the base station is completed, the number N of beams that the base station can generate can generally be determined. Of course, the number of candidate beams mentioned above can also be determined by the system configuration.

Second, the number K of the hierarchical beam selection method is determined. The series K of the above-described hierarchical beam selection may be a fixed empirical value. For example, considering the complexity of the hierarchical beam selection method, the number of stages K=3 of beam selection is directly set when the system is configured. The number K of the beam selection may also be determined according to specific application scenarios and requirements. For example, for a system with a relatively high delay requirement, the beam selection level K may be reduced to reduce the delay.

Third, the beams included in each of the first to Kth order beams are determined based on the N candidate beams and the number of stages K of the beam selection. In the example of the present application, the beams of the first to the Kth stages need to meet the following requirements:

1) Each beam of the i-th level corresponds to two or more beams of the i+1th order, where i=[1, K-1].

2) The beams of the i+1th level all correspond to one i-th beam.

3) The width of the i-th beam will be greater than the width of the i+1th beam.

4) The Kth order beam contains the above N candidate beams.

5) The directions of the respective beams of the i-th stage are respectively related to the directions of the two or more corresponding i+1th-order beams. Specifically, the coefficient of the coefficient of a certain i-th beam and the coefficient of the corresponding two or more i+1th-order beams may be greater than a preset threshold. That is, if the correlation coefficient of the two beam coefficients is greater than a preset threshold, the two beams are considered to be related; otherwise, the two beams are considered uncorrelated. The coefficient of the above beam may specifically be an Array Factor of the beam.

The above-mentioned level 1 to level K beams may also satisfy the requirement that the width of the i-th beam will be greater than the width of the i+1th beam.

Figure 1 shows an example of a determined beam of each stage. In this example, there are 8 candidate beams and the number of stages of beam selection is 3. As shown in Figure 1, in this example, there are two first-level beams (Level 1), and beams B ₁ and B ₂ , each of which corresponds to 2 of the 4 beams of the second-level beam (Level 2). Beams. For example, beam B ₁ corresponds to beams B ₁₁ and B ₁₂ , and beam B ₂ corresponds to beams B ₂₁ and B ₂₂ . Each of the four beams of the second stage corresponds to two of the eight beams of the third stage beam (Level 3). For example, beam B ₁₁ corresponds to beams B ₁₁₁ and B ₁₁₂ , beam B ₁₂ corresponds to beams B ₁₂₁ and B ₁₂₂ , beam B ₂₁ corresponds to beams B ₂₁₁ and B ₂₁₂ , and beam B ₂₂ corresponds to beams B ₂₂₁ and B ₂₂₂ . The third level is 8 candidate beams B ₁₁₁ , B ₁₁₂ , B ₁₂₁ , B ₁₂₂ , B ₂₁₁ , B ₂₁₂ , B ₂₂₁ and B ₂₂₂ . It can be seen from FIG. 1 that the widths of the first two beams are greater than the widths of the four beams of the second stage, and the widths of the four beams of the second stage are respectively greater than the widths of the eight beams of the third stage. And beam B ₁ is related to the directions of beams B ₁₁ and B ₁₂ , beam B ₂ is related to the directions of beams B ₂₁ and B ₂₂ , beam B ₁₁ is related to the directions of beams B ₁₁₁ and B ₁₁₂ , beam B ₁₂ and beam B ₁₂₁ Related to the direction of B ₁₂₂ , beam B ₂₁ is related to the direction of beams B ₂₁₁ and B ₂₁₂ , and beam B ₂₂ is related to the directions of beams B ₂₂₁ and B ₂₂₂ .

After the above settings are completed, beam selection can be started. Figure 2 shows the beam selection method described in the examples of the present application. As shown in FIG. 2, the method includes the following steps:

Step 201: The base station sends each beam of the first level to the UE.

In the example of the present application, in the process of beam selection, the base station transmits to the UE a reference signal of each beam. It is referred to herein simply as a beam reference signal (BRS).

In order to send a BRS to the UE, the base station needs to perform related resource configuration in advance, that is, tell the UE which subframe or time instance to occupy and time and frequency in the time instance to send the BRS. In this example, the above configuration may be referred to as a BRS resource configuration. Generally, the base station may perform BRS resource configuration by using RRC control signaling or dynamic control signaling; or may trigger by dynamic signaling after the RRC pre-defined BRS resources; or may be pre-configured in each subframe or time instance. Package Contains BRS.

Generally, the base station needs to indicate in which subframe or time instance the UE base station will perform BRS transmission. For example, the BRS indicator bit BRS_ENABLE may be added to the downlink control information (DCI) related to the downlink transmission transmitted on the downlink control channel, where BRS_ENABLE=1 indicates that the base station will start transmitting the BRS. The UE will perform beam detection when it detects that the BRS indicator bit BRS_ENABLE is 1.

Step 202: The UE performs beam detection, finds the beam with the best reception performance as the selected beam, and feeds back the beam index (BI) of the selected beam to the base station.

In order for the UE to feed back the beam index of the selected beam to the base station, the base station also needs to pre-define the feedback mode of the UE and perform related configuration, that is, inform the UE which feedback mode to use for feedback. In the present example, the feedback mode may include: 1) no feedback required; 2) feedback only the beam index of the selected beam; and 3) feedback channel quality indication (CQI, Channel) in addition to feedback of the beam index of the selected beam Quality Indicator, RI (Rank Indication), Precoding Matrix Indicator (PMI), and the like.

In general, it is also necessary to add an additional feedback mode indicator bit to indicate which feedback mode the UE uses for feedback. For example, the feedback mode indication bit FEEDBACK_MODE is added to the DCI related to the downlink transmission transmitted on the downlink control channel, where FEEDBACK_MODE=0 indicates that feedback is not required; FEEDBACK_MODE=1 indicates that the UE only needs to feed back the beam index of the selected beam; FEEDBACK_MODE = 2 indicates that the UE not only needs to feed back the beam index of the selected beam but also needs to feed back the current parameters such as CQI, RI and PMI. In this case, the UE will perform corresponding feedback according to the indication of the feedback mode indication bit. For example, when the UE detects FEEDBACK_MODE=1, only the beam index of the selected beam will be fed back; when the UE detects FEEDBACK_MODE=2, the beam index, CQI, RI and PMI of the selected beam will be fed back.

Regarding the timing at which the UE performs feedback, a minimum interval for reference signal (RS) transmission and channel state indication (CSI) feedback is defined in the Long Term Evolution System (LTE). Therefore, in the example of the present invention, the UE can determine the timing of the feedback in the following two ways:

(1) The timing of the feedback is determined by the transmission time of the reference signal. If the reference signal is received at the Xth time, the UE will feedback at the time of X+N.

(2) The feedback time is determined by the CSI feedback trigger (Trigger), for example, the UE will feedback after receiving the CSI feedback trigger signal.

Step 203: The base station receives the beam index fed back by the UE, and determines a beam corresponding to the received beam index.

In this step, the base station can directly determine the beam selected by the UE according to the received beam index.

Step 204: The base station determines whether the determined beam is a K-th beam. If the determined beam is not the K-th beam, step 205 is performed. If the determined beam is the K-th beam, step 206 is performed.

Step 205: The base station sends each beam in the next-level beam corresponding to the determined beam to the UE, and then returns to step 202.

In this step, the method for the base station to send the respective beams in the next-stage beam corresponding to the determined beam to the UE may refer to the foregoing step 201, and details are not described herein again.

Step 206: The base station uses the determined beam as the beam finally selected by the UE.

Through the above method of hierarchical beam selection, it is not necessary to send candidate beams to the UE for measurement one by one, so that the overhead of the beam selection process can be greatly reduced in the case where the number of candidate beams is large.

Figure 3 shows the process of beam selection between a base station and a single UE with only one UE. 3, the first resource locations shaded portion shown in the downlink subframe # 0 transmits a reference signal stage 1 according to the first two beams B ₁ and B ₂ in FIG. After detecting the two beams, the UE selects the better performing beam B ₂ by measurement, and feeds back the beam index of the selected beam in the uplink subframe #5, that is, BI=2. Next, the base station transmits the reference signals of the two beams B ₂₁ and B ₂₂ in the second-order beam corresponding to the beam B ₂ shown in FIG. 1 at the resource position shown by the shaded portion in the downlink subframe #6. After detecting the two beams, the UE selects the beam B ₂₂ with better performance by measurement, and feeds back the beam index of the selected beam in the uplink subframe #10, that is, BI=22. Finally, the base station transmits the reference signals of the two beams B ₂₂₁ and B ₂₂₂ in the third-order beam corresponding to the beam B ₂₂ shown in FIG. 1 at the resource position shown by the shaded portion in the downlink subframe #11. After detecting the two beams, the UE selects the beam B ₂₂₂ with better performance by measurement, and feeds back the beam index of the selected beam in the uplink subframe #15, that is, BI=223, and according to the feedback mode indication. The bit indication also feeds back information such as current CQI, RI, and PMI. So far, the beam selection process is completed. It can be seen that through the three selection processes, the base station transmits a total of six beams, and the UE can accurately select the best beam from the eight candidate beams.

FIG. 4 shows a process in which a base station performs beam selection with a plurality of UEs in the case where there are multiple UEs. In this example, it is first assumed that the number of candidate beams is 512; the number of beams is selected to be three, that is, there are eight beams in each stage, and the beams of each stage correspond to eight beams of the next stage. The number of UEs covered by the base station is 10, including UE1, UE2, ..., UE10. In this case, as shown in FIG. 4, the base station first transmits a first reference signal level eight beams B ₁ to B ₈ of. After detecting the 8 beams, each UE selects a beam with better performance through measurement, UE1 and UE2 select beam B ₁ and feed back the corresponding BI; UE3 selects beam B ₂ and feeds back the corresponding the BI; the UE4 and UE5 selected beam B _3, and the feedback corresponding BI; UE6, UE7 and UE8 selected beam B _5, and the feedback corresponding BI; UE9 selected beam B _6, and the feedback corresponding BI And the UE 10 selects the beam B ₇ and feeds back the corresponding BI. Next, the base station transmits references of beams B ₁₁ to B ₁₈ , B ₂₁ to B ₂₈ , B ₃₁ to B ₃₈ , B ₅₁ to B ₅₈ , B ₆₁ to B _{68 ,} and B ₇₁ to B ₇₈ as shown in FIG. 4 , respectively. signal. After detecting the beams, each UE selects a beam with better performance by measurement, UE1 selects beam B ₁₁ and feeds back the corresponding BI; UE2 selects beam B ₁₅ and feeds back the corresponding BI; UE3 Beam B _{25 is} selected and the corresponding BI is fed back; UE4 selects beam B ₃₂ and feeds back the corresponding BI; UE5 selects beam B ₃₆ and feeds back the corresponding BI; UE6, UE7 and UE8 select beam B ₅₄ and feedback the corresponding BI; UE9 selects beam B ₆₇ and feeds back the corresponding BI; and UE 10 selects beam B ₇₂ and feeds back the corresponding BI. Then, the base station transmits the reference signals of the third-order beams corresponding to the beams according to the beams selected by the UE. Finally, each UE selects the best performing beam according to the detection result of each beam, and feeds back the beam index of the selected beam and CQI, RI, and PMI to the base station. As shown in FIG. 4, in this example, from the third beam transmission process of the first level to the third stage, the number of beams transmitted by the base station to the UE is 8+6х8+8х8=120, but all candidate beams have 512. One. Therefore, the hierarchical beam selection method can greatly reduce the number of beams that the base station needs to transmit, thereby greatly reducing the overhead of the beam selection process.

In addition, as mentioned earlier, in the 5G era, more antennas and more beams can be obtained by combining massive MIMO technology and beamforming technology, and the beam width is narrower and narrower, thereby achieving more precise Directive service. However, as the beam width is narrowed, the beam will be affected by phase noise, which affects the accuracy of beam selection and the quality of communication. Therefore, in the multi-stage beam of the method of the present application, the upper-level beam is required to cover the corresponding lower-level beam, that is, the width of the upper-level beam is greater than the width of the lower-level beam. Therefore, the UE firstly uses a beam with a wide width. The choice is selected from the narrower beam, so that the influence of phase noise on beam selection accuracy can be better resisted, the accuracy of beam selection is improved, and communication quality is ensured.

Furthermore, in order to further combat the influence of phase noise on beam selection accuracy, the present application also proposes a beam selection method. In the method, after determining the candidate beam finally selected by the UE, further performing phase adjustment on the candidate beam finally selected by the UE, and The adjusted beam is sent to the UE. After performing beam detection on the phase-adjusted beam, the UE re-feeds the beam index of the selected beam to the base station. At this time, the base station may determine the phase-adjusted candidate beam selected by the UE. In the method, by performing phase adjustment on the candidate beam selected by the UE, the beam can be accurately aligned with the UE, thereby avoiding the influence of phase noise on beam selection accuracy and communication quality.

Figure 5 shows the beam selection method described in the examples of the present application. As shown in FIG. 5, the method includes the following steps:

Step 501: The base station sends each beam of the first level to the UE.

Step 502: The UE performs beam detection, finds the beam with the best reception performance as the selected beam, and feeds back the beam index (BI) of the selected beam to the base station.

Step 503: The base station receives the beam index fed back by the UE, and determines a beam corresponding to the received beam index.

Step 504: The base station determines whether the determined beam is a K-th beam. If the determined beam is not the K-th beam, step 505 is performed. If the determined beam is the K-th beam, step 506 is performed.

Step 505: The base station sends each beam in the next-level beam corresponding to the determined beam to the UE, and then returns to step 502.

The implementation methods of the foregoing steps 501 to 505 may be the same as the implementation methods of the foregoing steps 201 to 205, and are not described herein.

Step 506: The base station rotates the beam selected by the UE in a clockwise direction and a counterclockwise direction with a predetermined rotation precision s times, and obtains 2s beams, wherein each two adjacent The angles between the beams differ by one rotation accuracy. Where s is a natural number.

In this example, the setting of the rotation precision and the number of rotations s may be determined according to the width of the candidate beam and the angle between adjacent candidate beams, and each of the 2s+1 beams is guaranteed. Adjacent beams are only offset by a small angle and are not closer to other candidate beams after the offset.

Step 507: The base station sends the obtained 2s beams together with the UE selected beam to the UE.

In this step, the base station will transmit a total of 2s+1 beams of BRS to the UE.

Step 508: The UE performs beam detection, finds the beam with the best reception performance as the selected beam, and feeds back the beam index (BI) of the selected beam to the base station.

Step 509: The base station receives the beam index fed back by the UE, and determines a beam corresponding to the received beam index.

Step 510: The base station uses the determined beam as the final selected beam of the UE.

The above steps 506-510 implement fine adjustment of the phase of the selected beam, so that the selected beam can be more accurately aligned to the UE, effectively avoiding the influence of phase noise on beam selection accuracy and communication quality.

Figure 6 shows an example of the above-described phase fine adjustment of the selected beam. In the example shown in Fig. 6, it is assumed that s = 2. In this example, the base station first rotates the candidate beam B ₂₁₂ selected by the UE by a rotation precision twice in a counterclockwise and clockwise direction to obtain four beams B _212-2 , B _{212-1 ,} and B ₂₁₂₊₁ , B _{212 . +2} . In this case, the base station will transmit the BRS of the following five beams B _212-2 , B _212-1 , B ₂₁₂ , B ₂₁₂₊₁ and B ₂₁₂₊₂ to the UE. After the UE performs beam detection, the UE selects and feeds back B ₂₁₂₊₁ . In this case, the base station can determine that beam B ₂₁₂₊₁ can be more accurately aligned to the UE.

As an alternative to the above step 510, after performing step 509, the base station may further perform the following process as shown in FIG. 7:

Step 510A, determining whether the currently determined beam is the most edged beam obtained by rotation, and if yes, executing step 510B; if not, executing step 510C.

Step 510B: The base station uses the determined beam as the finally selected beam of the UE.

Step 510C: The base station continues to focus on the beam selected by the UE, and the beam is followed. The hour hand and the counterclockwise direction continue to rotate the preset rotation precision s times, and a total of 2 s beams are obtained, wherein the angle between each two adjacent beams differs by one rotation precision. Where s is a natural number.

Step 510D: The base station sends the obtained 2s beams together with the UE selected beam to the UE, and then returns to step 508.

The above steps 506-509, 510A-510D implement fine adjustment of the phase of the selected beam, so that the selected beam can be more accurately aligned to the UE, effectively avoiding the influence of phase noise on beam selection accuracy and communication quality.

Figures 8a and 8b show an example of the above-described phase fine adjustment of the selected beam. In the examples shown in Figures 8a and 8b, s = 1 is assumed. In this example, the base station first rotates the candidate beam B ₁₂₁ selected by the UE by one rotation precision in a counterclockwise direction and a clockwise direction to obtain two beams B _121-1 and B ₁₂₁₊₁ . In this case, as shown in Figure 8a, the base station will transmit the following three beams B _121-1 , B ₁₂₁ and B ₁₂₁₊₁ to the UE. After performing beam detection, the UE selects and feeds back B ₁₂₁₊₁ . In this case, the base station will continue to rotate one rotation counterclockwise and clockwise respectively around the beam B ₁₂₁₊₁ to obtain two beams B ₁₂₁ and B ₁₂₁₊₂ . In this case, as shown in Figure 8b, the base station will transmit the following three beams B ₁₂₁ , B ₁₂₁₊₁ and B ₁₂₁₊₂ to the UE. At this time, after the beam detection, if the UE selects the beam B ₁₂₁₊₁ , the beam B ₁₂₁₊₁ is the beam finally selected by the UE. If the UE selects beam B ₁₂₁₊₂ , the base station will continue to rotate counterclockwise and clockwise around beam B ₁₂₁₊₂ to obtain a new beam, and continue to send to the UE for selection until the UE finds the final beam.

Corresponding to the above beam selection method, an example of the present application also provides a base station implementing the beam selection method described above. Figure 9 shows the internal structure of the base station described in the examples of the present application. As shown in FIG. 9, the base station includes:

The configuration module 901 is configured to perform beam selection configuration, and determine a correspondence between the first-level to the K-th level beams and the beams of the levels; wherein the configuration module 901 is configured with the first Class to level K beams must meet the requirements described above;

a beam reference signal sending module 902, configured to send a beam reference signal to the UE;

The feedback receiving module 903 is configured to receive a beam index fed back by the UE.

The control module 904 is configured to control the beam reference signal sending module 902 to send the beam reference signal of the first stage beam configured by the configuration module 901 to the UE; after the feedback receiving module 903 receives the beam index fed back by the UE, determine the feedback beam of the UE. Indexing the corresponding beam, and determining whether the beam is a K-th order beam. If yes, the beam is the UE finally selected beam; if not, the control beam reference signal sending module 902 sends the beam corresponding to the next to the UE. Beam reference signal of the stage beam.

The base station may further include: a phase adjustment module 905, configured to perform phase adjustment on the beam selected by the UE, and control a beam reference signal of the beam after the phase adjustment of the beam reference signal sending module 902; and receive the UE in the feedback receiving module 903. After the feedback of the beam index, the beam corresponding to the feedback beam index of the UE is determined as the beam finally selected by the UE.

The phase adjustment module 905 can perform phase adjustment by using the methods of the above steps 506-510 or the methods of steps 506-509, 510A-510D.

As described above, the foregoing method for performing beam selection can greatly reduce the signaling overhead of the beam selection process by using the method of hierarchical beam selection, and the scheme can also be effective because the width of the configured upper beam is larger than the width of the lower beam. The effect of anti-phase noise on beam selection accuracy and communication quality, that is, improving the accuracy of beam selection, and thus improving the communication quality of the system.

In addition, the block diagram used in the description of the above embodiment shows a block in units of functions. These functional blocks (structural units) are implemented by any combination of hardware and/or software. Further, the means for realizing each functional block is not particularly limited. That is, each functional block may be implemented by one device that is physically and/or logically combined, or two or more devices that are physically and/or logically separated. The connection is made directly and/or indirectly (e.g., by wire and/or wireless) to be implemented by the plurality of devices described above.

FIG. 10 is another schematic structural diagram of a base station according to an embodiment of the present application. As shown in FIG. 10, the base station includes a processor 1001, a memory 1002, a memory 1003, a communication device 1004, an input device 1005, an output device 1006, and a bus 1007.

Each function of the base station 1000 can be realized by reading a predetermined software (program) into hardware such as the processor 1001 and the memory 1002, thereby causing the processor 1001 to perform calculation and control communication by the communication device 1004. And controlling the reading and/or writing of data in the memory 1002 and the memory 1003.

In some embodiments, the processor 1003 stores machine readable instructions that are executable by the processor 1001 to perform the following operations:

a, pre-configuring the correspondence between the first-level to the K-th beam and the beams at each level; wherein K is a natural number;

b. transmitting each beam of the first level to the user terminal UE;

c. receiving a beam index fed back by the UE;

d. determining a beam corresponding to the received beam index,

If the determined beam is not the K-th beam, transmitting each beam in the next-level beam corresponding to the determined beam to the UE, and then returning to c;

If the determined beam is a Kth order beam, the determined beam is used as a candidate beam selected by the UE.

In the above description, the hardware structure of the base station 1000 may include one or more components shown in the drawings, or may not include some components.

For example, the processor 1001 only illustrates one, but may be multiple processors. In addition, the processing may be performed by one processor, or may be performed by one or more processors simultaneously, sequentially, or by other methods. In addition, the processor 1001 can pass one The above chips are installed.

The memory 1003 is a computer readable recording medium, and may be, for example, a read only memory (ROM), an EEPROM (Erasable Programmable ROM), an electrically programmable read only memory (EEPROM), or an electrically programmable read only memory (EEPROM). At least one of a random access memory (RAM) and other suitable storage medium is used. The memory 1003 may also be referred to as a register, a cache, a main memory (main storage device), or the like. The memory 1003 can store an executable program (program code), a software module, and the like for implementing the uplink data transmission method according to the embodiment of the present application. In addition, the base station may include a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD, Programmable Logic Device), and a field programmable gate array. Hardware such as (FPGA, Field Programmable Gate Array) can realize some or all of each functional block by this hardware. For example, the processor 1001 can be installed by at least one of these hardwares, respectively.

In addition, the terms used in the present specification and/or the terms required for understanding the present specification may be interchanged with terms having the same or similar meanings. For example, the channel and/or symbol can also be a signal (signaling). In addition, the signal can also be a message. The reference signal may also be simply referred to as an RS (Reference Signal), and may also be referred to as a pilot (Pilot), a pilot signal, or the like according to applicable standards.

Further, the information, parameters, and the like described in the present specification may be expressed by absolute values, may be represented by relative values with predetermined values, or may be represented by other corresponding information. For example, wireless resources can be indicated by a specified index. Further, the formula or the like using these parameters may be different from those explicitly disclosed in the present specification.

The information, signals, and the like described in this specification can be expressed using any of a variety of different techniques. For example, data, commands, and references that may be mentioned in all of the above descriptions. Orders, information, signals, bits, symbols, chips, etc. may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination thereof.

Further, information, signals, and the like may be output from the upper layer to the lower layer, and/or from the lower layer to the upper layer. Information, signals, etc. can be input or output via a plurality of network nodes.

Information or signals input or output can be stored in a specific place (such as memory) or managed by a management table. Information or signals input or output may be overwritten, updated or supplemented. The output information, signals, etc. can be deleted. The input information, signals, etc. can be sent to other devices.

The notification of the information is not limited to the mode/embodiment described in the specification, and may be performed by other methods. For example, the notification of the information may be through physical layer signaling (for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and upper layer signaling (for example, radio resource control). (RRC, Radio Resource Control) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB), Media Access Control (MAC) signaling ), other signals, or a combination thereof.

Further, the physical layer signaling may be referred to as L1/L2 (Layer 1/Layer 2) control information (L1/L2 control signal), L1 control information (L1 control signal), and the like. In addition, the RRC signaling may also be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like. Furthermore, the MAC signaling can be notified, for example, by a MAC Control Unit (MAC CE).

Further, the notification of the predetermined information (for example, the notification of "X") is not limited to being explicitly performed, and may be performed implicitly (for example, by not notifying the predetermined information or by notifying the other information).

Regarding the determination, it can be performed by a value (0 or 1) represented by 1 bit, or by a true or false value (boolean value) represented by true (true) or false (false), and can also be compared by numerical values ( For example, comparison with a predetermined value).

Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or other names, should be interpreted broadly to mean commands, command sets, code, code segments, program code, programs, sub- Programs, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, steps, functions, and the like.

Further, software, commands, information, and the like may be transmitted or received via a transmission medium. For example, when using wired technology (coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), etc.) and/or wireless technology (infrared, microwave, etc.) from a website, server, or other remote source In software, these wired technologies and/or wireless technologies are included within the definition of the transmission medium.

Terms such as "system" and "network" used in this specification are used interchangeably.

In this specification, "base station (BS, Base Station)", "radio base station", "eNB", "gNB", "cell", "sector", "cell group", "carrier", and "component carrier" Such terms are used interchangeably. The base station is sometimes referred to by a fixed station, a NodeB, an eNodeB (eNB), an access point, a transmission point, a reception point, a femto cell, a small cell, and the like.

A base station can accommodate one or more (eg, three) cells (also referred to as sectors). When the base station accommodates multiple cells, the entire coverage area of the base station can be divided into a plurality of smaller areas, and each smaller area can also pass through the base station subsystem (for example, a small indoor base station (RFH, remote head (RRH), Remote Radio Head))) to provide communication services. The term "cell" or "sector" refers to a portion or the entirety of the coverage area of a base station and/or base station subsystem that performs communication services in the coverage.

In this manual, "mobile station (MS, Mobile Station)", "user terminal (user The terms "terminal", "user equipment" and "terminal" can be used interchangeably. Base stations are sometimes fixed stations, NodeBs, eNodeBs (eNBs), access points (access points). ), the sending point, the receiving point, the femto cell, the small cell, etc. are called.

Mobile stations are also sometimes used by those skilled in the art as subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless Terminals, remote terminals, handsets, user agents, mobile clients, clients, or several other appropriate terms are used.

In addition, the wireless base station in this specification can also be replaced with a user terminal. For example, each mode/embodiment of the present invention can be applied to a configuration in which communication between a radio base station and a user terminal is replaced with communication between a plurality of user-to-device (D2D) devices. At this time, the function of the above-described eNB can be regarded as a function of the UE 700. In addition, words such as "upstream" and "downstream" can also be replaced with "side". For example, the uplink channel can also be replaced with a side channel.

Similarly, the user terminal in this specification can also be replaced with a wireless base station. At this time, the function of the above-described base station can be regarded as a function of the user terminal.

In the present specification, it is assumed that a specific operation performed by a base station is also performed by an upper node depending on the situation. Obviously, in a network composed of one or more network nodes having a base station, various actions for communication with the terminal can pass through the base station and more than one network other than the base station. The node may be considered, for example, but not limited to, a Mobility Management Entity (MME), a Serving-Gateway (S-GW, etc.), or a combination thereof.

The respective modes/embodiments described in the present specification may be used singly or in combination, and may be switched during use to be used. In addition, the various methods described in this specification The processing steps, sequences, flowcharts, and the like of the embodiment can be replaced unless there is no contradiction. For example, with regard to the methods described in the specification, various step units are given in an exemplary order, and are not limited to the specific order given.

The modes/embodiments described in this specification can be applied to use Long Term Evolution (LTE), Advanced Long Term Evolution (LTE-A, LTE-Advanced), and Long-Term Evolution (LTE-B, LTE-Beyond). Super 3rd generation mobile communication system (SUPER 3G), advanced international mobile communication (IMT-Advanced), 4th generation mobile communication system (4G, 4th generation mobile communication system), 5th generation mobile communication system (5G, 5th generation mobile Communication system), future radio access (FRA), new radio access technology (New-RAT, Radio Access Technology), new radio (NR, New Radio), new radio access (NX, New radio access) ), Next Generation Wireless Access (FX), Global System for Mobile Communications (GSM (registered trademark), Global System for Mobile communications), Code Division Multiple Access 2000 (CDMA2000), Super Mobile Broadband (UMB) , Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra Wideband (UWB, Ultra-WideBand), Bluetooth (Bl Uetooth (registered trademark), systems of other suitable wireless communication methods, and/or next generation systems that are extended based on them.

The description "as is" used in the present specification does not mean "based only" unless it is clearly stated in other paragraphs. In other words, the term "according to" means both "based only on" and "at least based on".

The term "determination" used in the present specification sometimes includes various actions. For example, regarding "judgment (determination)", calculation, calculation, processing, deriving, investigating, looking up (eg, table, database, or other) may be performed. Search in the data structure), confirmation (ascertaining) and the like are considered to be "judgment (determination)". Further, regarding "judgment (determination)", reception (for example, receiving information), transmission (for example, transmission of information), input (input), output (output), and access (for example) may also be performed (for example, Accessing data in memory, etc. is considered to be "judgment (determination)". Further, regarding "judgment (determination)", it is also possible to consider "resolving", "selecting", selecting (choosing), establishing (comparing), comparing (comparing), etc. as "judging (determining)". That is to say, regarding "judgment (determination)", several actions can be regarded as performing "judgment (determination)".

The terms "connected" or "coupled" as used in the specification, or any variant thereof, mean any direct or indirect connection or combination between two or more units, This includes the case where there is one or more intermediate units between two units that are "connected" or "coupled" to each other. The combination or connection between the units may be physical, logical, or a combination of the two. For example, "connection" can also be replaced with "access". When used in this specification, two units may be considered to be electrically connected by using one or more wires, cables, and/or printed, and as a non-limiting and non-exhaustive example by using a radio frequency region. The electromagnetic energy of the wavelength of the region, the microwave region, and/or the light (both visible light and invisible light) is "connected" or "bonded" to each other.

When the terms "including", "comprising", and variations thereof are used in the specification or the claims, these terms are as open as the term "having". Further, the term "or" as used in the specification or the claims is not an exclusive or exclusive.

The above description is only an example of the present application, and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application are included in the scope of the present application. within.

Claims (17)

1. A beam selection method, comprising:

   a, pre-configuring the correspondence between the first-level to the K-th beam and the beams at each level; wherein K is a natural number;

   b. transmitting each beam of the first level to the user terminal UE;

   c. receiving a beam index fed back by the UE;

   d. determining a beam corresponding to the received beam index,

   If the determined beam is not the K-th beam, transmitting each beam in the next-level beam corresponding to the determined beam to the UE, and then returning to c;

   If the determined beam is a Kth order beam, the determined beam is used as a candidate beam selected by the UE.
2. The method according to claim 1, wherein said first to Kth order beams satisfy the following conditions:

   Each beam of the i-th level corresponds to two or more beams of the i+1th level;

   The beams of the i+1th level all correspond to one i-th beam;

   The K-th beam contains N candidate beams, N is a natural number;

   The direction of each beam of the i-th stage is respectively related to the direction of two or more corresponding i+1th-order beams; wherein i=[1, K-1].
3. The method according to claim 1 or 2, wherein the width of the ith stage beam is greater than the width of the i+1th order beam, wherein i = [1, K-1].
4. The method according to claim 2, wherein the direction of each beam of the i-th level is respectively related to the direction of the corresponding two or more i+1th-order beams:

   The correlation coefficient between the coefficient of the i-th beam and the coefficient of the corresponding i+1st-order beam is greater than a preset threshold.
5. The method of claim 4 wherein the coefficients of the beam comprise an array factor of beams.
6. The method according to claim 1, wherein the transmitting the respective beams of the first level to the user terminal UE comprises:

   Performing beam reference signal BRS resource configuration by radio resource control RRC signaling or dynamic control signaling;

   The BRS of each beam of the first level is transmitted on the configured BRS resources.
7. The method according to claim 1, wherein the transmitting the respective beams of the first level to the user terminal UE comprises:

   Configuring a beam reference signal BRS resource in the RRC signaling in advance;

   Notifying the UE to prepare to receive the BRS by dynamic signaling when preparing to transmit the BRS;

   The BRS of each beam of the first level is transmitted on the configured BRS resources.
8. The method according to claim 1, wherein the transmitting, to the UE, each of the next-level beams corresponding to the determined beam comprises:

   Performing beam reference signal BRS resource configuration by radio resource control RRC signaling or dynamic control signaling;

   The BRS of each beam of the next level is transmitted on the configured BRS resource.
9. The method according to claim 1, wherein the transmitting, to the UE, each of the next-level beams corresponding to the determined beam comprises:

   Configuring a beam reference signal BRS resource in the RRC signaling in advance;

   Notifying the UE to prepare to receive the BRS by dynamic signaling when preparing to transmit the BRS;

   The BRS of each beam of the next level is transmitted on the configured BRS resource.
10. The method according to claim 7 or 9, wherein the notifying the UE to prepare to receive the BRS by dynamic signaling comprises:

    Downlink control information DCI related to downlink transmission transmitted on the downlink control channel Adding a BRS indicator bit; wherein, when the BRS indicator bit is 1, it indicates that the base station will start to send the BRS;

    The BRS indicator bit is set to 1 when it is ready to transmit the BRS.
11. The method according to claim 1, further comprising: notifying a UE of a mode of feeding back a beam index; wherein, the mode of the feedback beam index comprises: no feedback is required; only feedbacking a beam index of the selected beam; and removing feedback In addition to the beam index of the selected beam, the channel quality indication CQI, the rank indication RI and the precoding matrix indication PMI are also required to be fed back.
12. The method according to claim 11, wherein the mode of notifying the UE of the feedback beam index comprises:

    Adding a feedback mode indication bit on the DCI related to the downlink transmission transmitted on the downlink control channel, where the feedback mode indication bit is 0 indicating that no feedback is needed; and the feedback mode indication bit is 1 indicating that only feedback is selected Beam index of the beam; the feedback mode indication bit of 2 indicates that not only the beam index of the selected beam needs to be fed back but also the current CQI, RI and PMI need to be fed back.
13. The method according to claim 1, wherein the determining the selected beam as the candidate beam selected by the UE comprises:

    Performing phase adjustment on the determined beam, and transmitting a beam reference signal of the phase adjusted beam to the UE;

    Receiving a beam index fed back by the UE;

    The beam corresponding to the feedback beam index of the UE is determined as the beam selected by the UE.
14. The method of claim 13 wherein said phase adjusting said determined beam comprises:

    Centering on the determined beam, the determined beam is rotated clockwise and counterclockwise by a predetermined rotation precision s times to obtain 2s beams, wherein the angle between each two adjacent beams is different. Rotation accuracy; where s is a natural number.
15. A base station, comprising:

    processor;

    a memory coupled to the processor; the memory having a machine readable instruction module executable by the processor; the machine readable instruction module comprising:

    a configuration module, configured to perform beam selection configuration, and determine a correspondence between the first-level to the K-th order beams and the beams at each level; wherein K is a natural number;

    a beam reference signal sending module, configured to send a beam reference signal to the user terminal UE;

    a feedback receiving module, configured to receive a beam index fed back by the UE;

    a control module, configured to: control a beam reference signal sending module to send a beam reference signal of the first-order beam configured by the configuration module to the UE; and after the feedback receiving module receives the beam index fed back by the UE, determine a beam corresponding to the feedback beam index of the UE And determining whether the beam is a K-th beam, if yes, the beam is a beam selected by the UE; if not, the control beam reference signal sending module sends a beam reference signal of the next-stage beam corresponding to the beam to the UE .
16. The base war of claim 15 further comprising:

    a phase adjustment module, configured to perform phase adjustment on a beam selected by the UE, and control a beam reference signal sending module to send a beam reference signal of the phase-adjusted beam; and after the feedback receiving module receives the beam index fed back by the UE, determine the feedback of the UE. The beam corresponding to the beam index serves as the beam selected by the UE.
17. A non-transitory computer readable storage medium, wherein the storage medium stores machine readable instructions, the machine readable instructions being executable by a processor to:

    a, pre-configuring the correspondence between the first-level to the K-th beam and the beams at each level; wherein K is a natural number;

    b. transmitting each beam of the first level to the user terminal UE;

    c. receiving a beam index fed back by the UE;

    d. determining a beam corresponding to the received beam index,

    If the determined beam is not the K-th beam, transmitting each beam in the next-level beam corresponding to the determined beam to the UE, and then returning to c;

    If the determined beam is a Kth order beam, the determined beam is used as a candidate beam selected by the UE.

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